关键词: 超细分级机, 切割粒径, 颗粒轨迹, 数值模拟

Abstract: In order to study the cut size of a superfine classifier, computational fluid dynamics was used to simulate the gas-solid two-phase flow in the classifier. The RNG k-ε turbulence model was adopted to describe the gas phase, and the particle stochastic trajectory model was used to describe the solid phase. The physical mechanism of particle movement and the classification process in a superfine classifier was revealed by analyzing the relationship between particle tracks and cut size. By analyzing the change of cut size, the effects of rotational speed, air volume, feeding concentration and material density on cut size were established. The results showed that in the theoretical calculation of cut size, ignoring the effect of blade thickness would lead to overly small calculated value. When rotational speed was low （450 r/min，600 r/min）, the simulation value and calculated value had a large difference due tor the effect of local turbulence, and the max error was 13.58%. Compared with air volume, the effect of rotational speed on cut size was much more significant. The simulation cut size value agreed well with theoretical calculation. The results provide a new method of obtaining the cut size of a superfine classifier.

Key words: superfine classifier, cut size, particle tracks, numerical simulation